Door operating mechanism



y 1940- I A. o. WILLIAMS 2,207,365

DOOR OPERATING MECHANISM Filed April 20, 1956 4 Sheets-Sheet 1 AL I Q [521/022 for July 9, 1940. A. o. WILLIAMS DOOR OPERATING MECHANISM Filed April 20, 1936 4 Sheets-Sheet 2 Q wi h Q July 1940. A. o. WILLIAMS DOOR OPERATING MECHANISM Filed April 20. 1936 4 Sheets-Sheet 5 July 9', 1940. A. o. WILLIAMS DOOR OPERATING MECHANISM Filed April 20; 1956 4 Sheets-Sheet 4 Patented July 9, 1940 UNITED STATES DOOR OPERATING MECHANISM Alfred 0. Williams, Battle Creek, Mich., assignor, by mesne assignments, to Clark Equipment Company, Buchanan, Michigan Application April 20,

9 Claims.

This invention relates to door operating mechanisms, and more particularly is directed to a door operating mechanism for vehicles such as busses, street cars, rail cars and the like.

Broadly, the present invention comprises an operating mechanism wherein as the arms carrying the door are rotated in one direction, the door itself is rotated relative to these arms'in' the opposite direction. The construction disclosed herein provides an actuating mechanism whereby the two doors closing a door well of a vehicle such as described are simultaneously swung in opposite directions into position within the door well substantially normal to the plane of the opening and at the lateral edges thereof.

One object of the present invention is to provide a door actuating mechanism for swinging two doors away from closed position into open position without allowing any substantial portion of the doors to pass through the space forming the door well. This: is of distinct advantage where the doors are employed in passenger vehicles and the space forming the door well is normally occupied by one or more, passengers desiring egress from the vehicle.

Another object of the present invention is to provide means for rotating the doors in opposite directions out of closed position by the unidirectional movement of a single actuating member, and to return the doors to closed position upon reverse movement of this member. This simplifies the operation of the actuating mechanism while retaining the feature of not carrying any substantial portion of the doors through the door well.

It has been found that withcertain types of door constructions now in use, it is impossible to open the doors except by mechanical operation of the actuating mechanism. This is undesirable, since if the mechanism for any reason fails,' the passengers are not capable of leaving the vehicle. Further, such construction constitute a real hazard in case of fire, accident or the like, and contribute to increase the panic of the passengers in such situations. In the present construction, this. condition is eliminated by providing for initial outward movement of the meet--. ing edges of the doors, with a lost motion connection so that after predetermined movement the doors canbe crowded open by pressureon the inner surface thereof, this movement of the doors serving to move the actuating mechanism to door open position independently of application of the normal energizing force to the actuating mechanism. This insures that the pas-- Mich, a corporation of 1936, Serial No. 75,503.

sengers can leave the vehicle even if the operating mechanism is not in operative condition.

The present door actuating mechanism can-be installed in a vehicle of the class described eitherfor operating doors at the front or rear of the vehicle, or doors placed midway between the ends thereof, since its underlying principles are the same in. all cases, and only mechanical adaptation is necessary to provide for its use in any location. Primarily, it comprises an actu-f ating member which may-take the form of a longitudinally movable member connected at its ends to linkswhich in turn are rotated by longitudinal movement of said member to effect rotation of carrier brackets which support the doors An idler gear arrangement changes the rotational direction at one end of the actuating member into rotation in the opposite direction,- whereby the brackets swing inwardly of the door well in opposite directions toward the side walls defining the Well. The doors are pivotally mounted at substantially the median vertical plane thereof to the brackets, and suitable rack and pinion means rotatable about a fixed point and actuated by rotation of said brackets serves to rotate each door in a direction opposite to the direction of rotation of the bracket supporting the same as the corresponding bracket swings inwardly under the influence of the actuating member. Thus as' the doors are being bodily moved in a horizontal arc, they are simultaneously rotated in the opposite direction. The mechanism is so designedthat the doors reach a plane parallel to the defining lateral surfaces of the well as the brackets reach their full open position, insuring that minimum space within the well will be occupied by the doors in their full open position. By varying the pivotal position of the rack, the degree of-rotation of the door can be correspondingly varied as desired.

The present construction lends itself to simplified and economical manufacture and assembly, and the operating parts are so disposed as to be immediately available for inspection, replacement and repair. Most of the parts can. be made of castings or standard machine parts, so that the cost of manufacturing 'is maintained at a minimum. l t

Other objects and advantages of the present invention will' appear more fully from the following detailed'description which, taken in conjunction with the accompanying'drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In. the drawings:

Figure 1 is a side elevational view, partially in section, showing one form of the present invention;

Figure 2 is a top plan view of the operating mechanism, the dotted lines indicating the door open position;

Figure 3 is a sectional view of the actuating cylinder;

Figure 4 is a top plan view, with portions broken away, of the upper door carrying bracket;

Figure 5 is a sectional view taken substantially on line 5-5 of Figure 2;

Figure 6 is a somewhat diagrammatic illustration of the door movement with respect to the movement of the supporting arm or bracket;

Figure 7 is a sectional view of a modified rack arm construction;

Figure 8 is an enlarged sectional view through a modified form of actuating cylinder;

Figure 9 is a sectional view through apreferred form of actuating cylinder; and

Figure 10 is a sectional view taken on line I0-I0 of Figure 9.

Referring now in detail to the drawings, I have disclosed in Figure l a pair of doors 5 and 6, supported at their lower ends on pivoting studs 1 and 1, respectively, carried by the extending arms 8 and 8', which arms at their opposite ends are pivoted on suitable thrust bearings 9 and 9 carried within the bearing supports I0 and I0. I

At their upper ends the doors 5 and E are provided with offset pivot studs I2 and I2 mounted in fixed position above the upper edge of the door by the supporting plates I3 and I3 which are riveted or otherwise suitably secured to the doors. I

It will be noted that the studs I, 1, l2 and I2 serve to support the doors for rotation about a vertical plane extending centrally of each of the door members.

As shown in Figure 2, the door well I 4 comprises the space formed by a lateral defining wall I5, a vertically extending wall I 5 disposed above the doors 5 and 6, and a central vertical partition member I I, disposed between the respective pairs of corresponding doors 5 and ii.

In constructions of this type it is customary to provide doors either at the forward end of a street car or the like, at the rear end of such vehicle, or midway between the ends. The doors usually are disposed in pairs there being two pairs at each door opening, the respective pairs being separably operable into and out of closed position. Thus, in Figure 2, a second pair of doors corresponding to the doors 5 and 6 would be disposed to the right of the central partition I1, and would be operated in the same manner. One such door is diagrammatically indicated at 5A. If the door opening is at either end of the vehicle due to the tapering effect produced at the ends for streamlining purposes, the outer surface of the car will extend at an angle with respect to transverse planes through the car. This angle is indicated between the partition I5, and the wall I6 forming the side wall of a vehicle and framing the upper and lower edge or the door opening. Of course, if the doors are disposed midway between. the ends of the vehic1e, the angle between the partition I5 and the wall I6 will be a right angle.

Mounted on a suitable supporting surface, such as a horizontal plate disposed above the door opening and within the outer wall I6, I provide a suitable bracket 20 having means 2| receiving rivets or the like for securing the same to the supporting surface. The bracket 20 is provided with a central offset portion containing a pair of inlet ports connected to the conduits 22 and 23. These inlet ports communicate with vertical passageways 24 and 25 which, intermediate their ends, open through horizontally extending passageways 26 and 21 as shown in Figure 3. The inner face portion of the offset boss is provided with a flanged'surface 28 to which is secured a piston member 29 as shown by means of bolts 30.

The member 29 is provided with longitudinally extending passageways 32 and 33 communicating respectively, by normally extending passageways, with the transverse passageways 26 and 21. It will thus be apparent that fluid admitted through conduit 22 to the port 24 will pass outwardly of the member 29 through the passageways 26 and 32, and similarly, fluid under pressure admitted through the conduit 23 will pass outwardly of the opposite end of the member 29 through passageways 21 and 33. No com munication between the conduits 22 and 23 is provided.

Each end of the member 29 is provided with a cup-shaped gasket member 35, secured thereto and having a central opening aligned with the respective passageways 32 and 33. Disposed about the member 29 and reciprocatory with respect thereto, I provide the cylinder 36 having the cut-away portion 3? for clearing the up-standing portion of the bracket 20. The cylinder 38 is closed at its ends by threaded cap members 38 and 39 which are provided with extending collar portions 30 and 52 preferably formed integral therewith and having vertical passageways extending therethrough.

It will be apparent that upon admission of fluid under pressure from the conduit 23 into the passageway 33, the cylinder 36 will move from the position shown in Figure 3 toward the right under the influence of the pressure built up in the right hand end of the cylinder. At the same time, fluid within the space 43 at the left hand end of the cylinder will be exhausted through the passageway 32 and the conduit 22 to allow movement of the cylinder. To effect movement in the opposite direction, the conduit 23 will be opened to exhaust and fluid under pressure will be supplied through passageway to the space 43 to move the cylinder 36 to the left. i

It is advantageous to provide an operating mechanism in which a cushioning effect is pro vided as the doors approach fully open and fully closed position. The present invention attains this feature by the structure shown in Figure 8.

Considering now Figure 8 in detail, it will be noted that the passage 32 in the piston 29 is enlarged in diameter, and is adapted to receive the pilot I25 of the modified cap member 38', which pilot is provided with an axial passage I26. At its outer end, the pilot is provided with an offset extension I21, which has a slight clearance as indicated at I28 with respect to the in ternal surface of cylinder 36. I

A radial passage I29-extends from the passage I26 outward through the extension I21, and is provided with a valve seat normally engaged by the ball check valve I 30. The ball I30 cannot escape from the passage by reason of the relatively small clearance at I28 with respect to the cylinder. The end of cap member 33 is provided. with a radial passage I32 extending from passage I26 outwardly tothe normally extending bore or passage I33 communicating with the interior of the cylinder 36. A suitable needle valve member I34, carried by the cap member 38', is adjustable toward and away from valve seat I35 in passage I32 to meter the flow of fluid therethrough. Except for these modifications, the cap member 38' corresponds to the cap member 38 of Figure 3. A similar construction is provided at the opposite end of the cylinder 36 in place of cap member 39.

In operation, upon movement of cylinder 36 to the right, as viewed inFigure 8, the fluid between the cap member and the stationary piston will be exhausted through passages I33, I32 and past valve seat I35 into passage I26. However, any fluid from the interior of cylinder 36 which attempts to escape by passing through passage I29 into passage I26 will only serve to hold valve I38 on its seat, and consequently the exhaust of fluid pressure will be metered by valve I34.

As the cylinder nears the end of its movement in this direction, therefore, the fluid pressure in this end of the cylinder will restrain and cushion its movement so as to prevent the doors being forcibly slammed into their full open position.

In door closing movement, fluid under pressure is admitted to passage 32 and hence to passage I26. Under such conditions, however, the pressure unseats ball check valve I30, and this fluid can therefore escape directly into the interior of the left-hand end of cylinder 36. A portion of the fluid will also pass into the cylinder through passages I32 and I33. Thus there is so substantial restriction to the entrance of fluid under pressure into the actuating end of the cylinder. However, the doors are cushioned against abrupt movement into fully closed position by the restraining action at the opposite end of the cylinder, corresponding to that previously described.

Secured in collar 48 is a stud portion 44 of a link 45, the stud portion being held in position within suitable bearing means in the collar such as a bronze bushing or the like, by means of the nut 46. The link 45 is threaded at its opposite end as indicated at 41 in Figure 2, and is received within a suitable clamp 48 having internally threaded portions receiving the link 45, and a second link 49 which corresponds to the link 45 but is provided with a downwardly extending portion 58 received within the bearing collar 52 of the arm 53. The arm 53 is mounted on a fixed pivot member 54 carried by the bracket 55 shown in Figure 5, and is keyed to a sprocket gear or pinion 56, mounted for rotation about the stud 54. Preferably, a suitable bronze bushing 57 is interposed between the hub of the pinion 56 and the stud 54 to facilitate rotation of the pinion with respect to the stud.

This pinion or idler gear 56 is adapted to mesh with a second gear 58 keyed to the reduced portion 59 of a shaft 68 whereby longitudinal movement of the links 45 and 49 caused by movement of cylinder 36 to the right will effect rotation of arm 53 and pinion 56 in a counter-clockwise direction as viewed in Figure 2, and will thus produce clockwise rotation of shaft 60 through the gear 58 keyed thereto and driven by pinion 56.

The shaft 68 at its lower end is provided with an offset portion 62 receiving the upper end of a cylindrical member 63 that, at its lower end is welded or otherwise secured to the bracket 8. A suitable stud shaft 64 is pressed into the lower end of the member 63 and has bearing support in the thrust bearings 9, the stud shaft 64 having a roughened surface for keying it for conjoint rotation with the member 63 and shaft 68.

Considering now in detail Figure 5, it will be noted that the bracket 55 is provided with an offset portion 66 which is adapted to carry a depending stud member 6! having a headed portion 68 at its lower end. The stud BI'is provided with a bronze bearing collar 69 forming a suitable bearing receiving the hub"! of a laterally extending stud I2. A split clamp nut I3 is threaded over the end of the stud I2 and also over the threaded end I4 of a rack arm I5 having the rack teeth I6 formed along one vertical surface thereof. A suitable nut 11, as shown in Figure 2, clamps the member I3 in position to fix the arm 15 with respect to shaft 61, whereby the arm may rotate about this shaft as a pivot.

As shown more clearly in Figures 4 and 5, the shaft 60 is provided with a roughened portion 18 adapted to receive a bracket member I9 mounted for conjoint rotation therewith. The bracket "I9 is provided with a peripheral wall portion forming a housing in which is disposed aroller member 82 mounted for free rotation on a stud shaft 83 carried by the bottom wall of the bracket. The roller has bearing engagement with the flat surface, opposite the toothed portion of the arm 15 to maintain the teeth of this arm in engagement with the pinion 84 carried by the stud I2 forming the upper door pivot. The pinion 84 is keyed to the stud I2 by means of the key 85, and a suitable cap plate 86 is secured over the top of the pinion to prevent the rack I5 from moving out of engagement vertically with respect to the pinion. The stud I2 is mounted for rotation relative to the bracket 19 by means of suitable bearings 81 carried in a boss portion 88 formed in the bottom wall of the bracket I9. A reinforcing rib 90 extends from the boss 88 to the hub portion of the bracket I9. Due to the lateral displacement of the pivots formed by shaft 60 and the stud 61, any horizontal swinging movement of the bracket I9 will result in rotation of the pinion 84 due to meshing engagement with the teeth of the rack arm I5, which in turn will rotate the stud I2 to cause corresponding rotation of the door 5. By the spacing between the pivot points, the degree of rotation of the door relative to the arcuate movement of the bracket can be determined, and this may be readily adjusted by varying the relative diameter of the pinion with respect to the rack, or by the spacing of the pivots.

In the operation of the mechanism thus far described, admission of fluid under pressure to the right hand end of the piston 35 will result in movement of the cylinder 36 to the right, as viewed in Figures 2 and 3, producing counterclockwise rotation of the arm 53. This results in clockwise rotation of the pinion 58, in turn producing clockwise rotation of the bracket 79. This tends to move the pinion 84 carried by the door stud I2 inwardly along the rack arm I5 resulting in the rotation of this pinion in a counter-clockwise direction to produce corresponding rotation of the door. The meeting edge 92 of the door will therefore move laterally away from the middle of the door opening and slightly outwardly, and will then rotate into final open position with the edge 92 disposed at the side of the opening and at the front edge thereof.

Considering now in detail Figure 6 which illustrates the movement of the door upon operation of the actuating mechanism, initial rotation of the shaft 68 results in clockwise rotation of the arm I9 moving the pivot stud I2 in an are indicated by the arrow 93. The bracket. I3 which carries the door 5 is offset so that the stud I2 and the bracket I9 lie inwardly of the door when the door is in closed position as shown in full lines. As the arm I9 moves to a position where the stud I2 occupies the position shown at I2, the door moves into a position indicated at 5, with the outer edge 92 simultaneously moving slightly outwardly of the door opening and away from the center of the opening. As the arm I9 then moves to the position shown at I2", the door moves into the position shown at 5", the edge 92 still being disposed outwardly of the door opening and the door itself rotating in a counter-clockwise direction about the pivot point I2. When the arm '79 reaches its full open position indicated at IZ, the door is moved into a position fiat against the side wall I5 of the door opening as indicated in dotted lines at 5".

For closing the door, the arm 19 merely reverses its pivotal movement about its pivot 50 and the door returns from its position against the wall I5 into a position closing the corresponding half of the door opening. Rotation of the shaft (it) produces corresponding rotation of the member 53 and likewise produces rotation of the arm 8 which has pivotal connection with the door I. Thus the door is supported between the studs I and 2 for rotation about a central vertical plane in a direction opposite to the arcuate rotative movement of the brackets I9 and 8. It will therefore be apparent that the door at no time moves bodily into the door opening but pivots in such a manner that it at no time obstructs this passage.

The operation for opening the door 6 is substantially similar except that the countershaft 54 may be omitted since the movement of the cylinder 36 is sufiicient to effect the proper direction of rotation of the shaft 60 which carries the bracket I3 supporting this door. Similar parts are indicated by corresponding primed reference numerals for the two actuating mechanisms, the arm 39' at the right hand end of the cylinder 3% being connected to an arm 95 which is mounted non-rotatively about the upper end of the shaft 69. This causes rotation of the corresponding bracket IQ' which carries the door pivots in an arc inwardly of the door opening. At the same time the rack I5 efiects a counterrotation of the door itself about a vertical plane passing centrally through the door and the door 6 therefore moves into a position against the side wall of the door opening as shown at 6 without passing through any substantial portion of the door well.

In this case, however, the brackets I9 and 8' move in a counter-clockwise direction inwardly of the door opening, while the door itself rotates in a clockwise direction about the studs 1 and I2 whereby the meeting edge 96 of the door 6 at no time passes into the door well I4 but preferably moves slightly outwardly of the door opening upon initial movement due to the location of the pivots ti and 69 and the engagement of the rack iI with the pinion 84. Upon movement of the cylinder 36 to the left for door closing movement, the arm 95 is rotated in a clockwise direction to produce corresponding rotation of the brackets i9 and 8 which carry the door outwardly, while the door at the same time rotates in a counter-clockwise direction into a common plane with the door 5 which is moving outwardly from the opposite side of the door well. The bracket 55', which corresponds somewhat to the bracket 55 at the left hand side of the Figure 2 is extended to provide for supporting the shaft I which corresponds to the shaft 60 associated with the door and which carries a pinion I02 corresponding to the pinion 58. A duplication of the operating mechanism thus far described is provided to the right of the bracket 55' for the purpose of actuating a similar pair of doors at the opposite sides of the partition IT. The cylinder 36 and the corresponding cylinder which controls the door 5-A and its companion door (not shown) may be operated simultaneously or independently as desired, preferably being operated independently so that either pair of doors may be opened at will.

It is distinctly advisable to have the meeting edges 92 and 95 of the doors 5 and 6 move slightly outwardly upon initial door opening movement in order that passengers standing in the doorway will not interfere in the operation of the doors nor be injured by the doors moving inwardly, and also to provide for outward movement caused by pressure internally of the doors to start the door mechanism in operation indepedently of the cylinder 36. When this cylinder or the control means becomes inoperative, a slight outward pressure on the meeting edges of the doors, with no pressure in either end of the cylinder 36, will cause the doors to be manually opened since this outward pressure will cause rotation of the racks which will in turn swing the brackets in counter directions to carry the doors into open position.

It should be noted that the brackets 19 and I9 are designed for right and left hand mounting and the side walls 80 and 80 are provided with cutaway portions I83 and I03 which provide for entrance of the rack arm thereinto, and also allow the brackets to swing into position about the pivots 67 and E7. The brackets are each provided with cover plates IM and IN which may be secured thereto in any suitable manner. These cover plates are provided with arcuate slots I05 as shown in Figure 4 to receive the depending boss portion of the extensions 66 and 66' of the brackets 55 and 55' and the hubs I0 and ID of the arms I2 and T2.

In an alternative form of the present invention, I have provided for a lost motion connection between the rack arm and its associated pivot whereby, if an obstruction is preventing initial movement of the door, the operating mechanism can begin its rotation while the rack remains stationary, and after slight movement of the operating mechanism, the door will then snap away from the obstruction and rotate into its fully open or fully closed position without damaging the actuating mechanism.

Thus in Figure 7 I provide the pivot stud IIII carried by a supporting bracket H2 which serves as a pivot for the arm H3 having the hub portion H4 pivotally engaged about the bearing bushing H5 carried by the stud. Adjacent its outer end, the arm II 3 is provided with a pin I I6 which engages in suitable slots IIl formed in a tubular extension H8 of the rack 1'5. The inner end of the tubular extension H8 is provided with the flanged collar H9 against which one end of the spring I20 engages. The spring I20 encircles the extension I I8 and at its opposite end bears against a supporting ring I22 which is held against axial movement by engagement with the pin H6. Thus it will be seen that the arm I5 has limited axial or telescoping movement with respect to the arm I I3, and this movement results in compression of the spring I20 whereby the spring is biased to return the arms to their normal position shown in Figure 7. Thus if for some reason an obstruction is placed between the meeting edges of the doors preventing them from closing fully, the operating mechanism can move to fully closed position which will result in compression of the spring I20 and upon removal of the obstruction, the springs will move the doors to their fully closed position. This is desirable to prevent accidents and is also effective to provide for opening the doors slightly when the operating mechanism is rendered inoperative, whereby they can be grasped and moved to their fully opened position. Such a connection can be applied to each of the rack arms. I

The amount of rotation of the brackets 19 and 19 is determined by the actuating mechanism 36 and the ratio of the gears 56 and 58. The amount of rotation of the brackets 19 and 19' is determined by the actuating mechanism 36 and the ratio of the gears 56 and 58. The amountv of rotation of the door with respect to the arms 19 and 15 is determined by the diameter and gear tooth ratio of the rack and pinion mechanism and by the spacing of the pivot points 60 and 61, and the corresponding pivots 60 and 61'. Thus the doors can be moved to a position at right angles with respect to their closed position while the arm 10 moves through only aportion of the arc, or if the side wall of the car is angled with respect to the door opening, the doors can be made tomove either a greater or lesser distance upon corresponding movement of the carrying arms. In one embodiment of the invention the doors move through an angle of 165 with respect to the arms carrying the same, while these arms move through'an arc of from '75 to 90. It will thus be apparent that the rate of angular movement of the doors can be made to vary. with respect to the rate of movement of the arms in any desired manner.

In Figures 9 and 10 I have disclosed a preferred embodiment of a construction for cushioning the movement of the doors into and out of closed and opened position. The supporting bracket. 20' corresponding to the bracket 20 of Figure 2 is provided with the two ports I40 and I42 which terminate in laterally extending openings I43 and I 44, respectively, communicating with the ports I45 and 546 of the stationary piston I41 which is bolted to the face I48 ofthe bracket 20 by means of a plurality'of bolts I49.

The piston I41 is of a form similar to that shown in Figure '3 but is provided with enlarged axially extending passageways I 50 and I52 directed toward opposite ends of the piston and provided adjacent the opposite ends with enlarged portions I53. Each end of the piston I41 is provided with a radially extending flange portion I54 which is of a diameter slightly less than the diameter of the interior of the cylinder I55. The cylinder I55 is provided at each end with a threaded cap member I56 closing the end and having an axially projecting stem portion I51 which is centered for reciprocal movement in the passageways I50 and I52. The stem I51 is axially bored to provide the passageway I56 which terminates in a radially extending passageway I59, as shown in detail in Figure 10, having a valve seat I controlled by the metering valve member I62 threaded radially into the cap member I56. The flow of fluid from the passageway 658 through the passageway I59 and past the valve seat I60 is controlled by the valve I62 which meters the escape of fluid through the opening I63 into the interior of the cylinder I55. Each of the cap members I56 is provided with an extending arm portion I66 corresponding to the arms 40 and 42 of the members 38 and 39 of Figure 3.

Secured to the outer face of the piston flanges I54 is a leather cup gasket I61 adapted to have sealing engagement with the internal surface of the cylinder I 55 and held into position by a plurality of screws I68 which also serve to position a plate-like spider member I69 in position.

Slidably mounted on the. external surface of the stem I51 is a sleeve valve member I10 having a radially extending flange I12 which is locked between the inner end of the spider member I69 and the face of the piston. A suitable resilient gasket member I13 seated in an annular recess formed at the outer end of the enlarged portion I 53 of the passageway I50 limits the reciprocal movement of the slide I10 with respect to the end of the piston. The spider member I69 is provided with a plurality of circumferentially spaced openings I14 which provide communication between the interior of the cylinder I55 between the piston and the cap I56 and the passageway I50.

In the operation of the structure shown in Figures 9 and 10 when fluid under pressure is admitted through the passageway I50 and port I45 into the passage I50, this fluid escapes through the enlarged passage I53 and the ports I14 into the interior of the cylinder between the cap member and the piston. A portion of the fluid also passes through the stem I51 and past the needle valve I62 into the interior of the cylinder. The increase of pressure in the interior of the cylinder forces the cylinder I55 to the left as viewed in Figure 9, and results in movement of the stem I51 axially outwardly of the passage I50. This results in the sleeve member closing ofi the port I 15, forming communication between the passageway I56 and the enlarged portion I53 of the passageway I50. This passage of fluid into the interior ofthe cylinder I55 between the gasket I61 and the cap I56 moves the cylinder into a position to open the doors to their full open position.

'In closing the doors, the passageway I42 is supplied with fluid under pressure which produces a corresponding flow of fluid through the passageway I52'at the opposite end of the piston and tends to move the cylinder I55 to the right. This results in inward movement of the stem I51 within the passageway I50 and produces an increasejin pressure of the fluid confined in the gasket I61 and the cap member I56 within the left hand end of the cylinder. The sleeve member I10 moves into position against the gasket I13 and due to the tapered surface I16, a sealing engagement between the flange I12 and the gasket I13 is provided. This prevents escape of fluid from the ports I14 past the flange I12 and the enlarged portion I53 and into the passage I50. As a result the fluid confined between the end of the cylinder and the piston must escape through the port I53 and past the needle valve I62 and into the passage I58. Since this path of flow is metered, it will be obvious that the fluid can escape only at a given rate and consequently, the cylinder will be cushioned against abrupt closing movement by reason of the body of fluid confined in the end at which it escapes at a slow rate into the passage I50 into the stem I51.

By adjusting the position of the valve I62, any desired cushioning eifect can be provided in accordance with the rate of closing which is to be effected.

It is obvious that during door opening movement the same type of cushioning action is produced at the right hand end of the cylinder I55 and consequently, the doors cannot be moved abruptly into their full open position, but are cushioned so as to at first move at a relatively fast rate in their opening movement and then slow down to any given movement as they near their full open position.

It is also to be pointed out that since the sleeve member ilfi closes the port H after a predetermined movement of the cylinder in door opening position, the full fluid pressure is not transmitted as rapidly to the head of the piston after the cylinder has reached a position such that the member ill) covers the port 115 and thus, the effective force tending to open the doors is reduced as the doors near their full open position. A similar action occurs at the opposite end of the cylinder during door closing movement.

It is therefore apparent that I have provided an effective mechanism for cushioning the doors as they move into fully opened and fully closed positions whereby their operation is accomplished with the least amount of strain on the mechanism, while yet maintaining an efficient rate of movement during the major portion of each operation.

I am aware that various changes in construction and details of operation can be made in the present invention without departing from the underlying features thereof, and I therefore do not intend to be limited, except as defined by the scope and spirit of the appended claims.

I claim:

1. In a door operating mechanism, a vertical shaft having a gear at one end thereof and having a pair of vertically spaced horizontal brackets provided at their extending ends with pivot supporting means, a door having pivots at the top and bottom thereof intermediate its lateral edges supported in said brackets, one of said brackets forming a housing about the adjacent door pivot, a pinion on one of said door pivots Within said housing, means pivoted independently of said shaft extending into said housing and engaging said pinion, means on the corresponding bracket holding said means in engagement with said pinion, and means engaging the gear on said shaft for rotating said shaft to swing the door bodily about the shaft as a center, said pinion engaging means rotating the door about its pivot in a direction opposite to the direction of rotation of said shaft.

2. A door mechanism comprising a door pivoted. intermediate its lateral edges, a supporting lever for the door pivoted outwardly of one edge of said door and forming a housing for the door pivot, means for rotating said lever through a predetermined arc, and means extending into said housing and engaging the door pivot and having an external pivot laterally offset from the pivot of said lever for producing a rotational movement of said door with respect to said lever through an are at least twice the are through which said lever rotates.

3. A bracket for a door operating mechanism of the class described comprising a substantially planar body member having a boss portion at one end thereof adapted to receive a supporting shaft, the body member being provided with a peripheral flange forming a cup-shaped recess, a thrust bearing portion in said recess adjacent the other end of said body member adapted to receive a pivot stud of a door, a cover for said bracket engaging the upper'edge of said flange and enclosing said pivot stud, said flange having an opening in the lateral surface thereof adapted to receive means extending thereinto for rotating said stud.

4. A bracket for a door operating mechanism of the class described comprising a substantially planar body member having a boss portion at one end thereof adapted to receive a supporting shaft, the body member being provided with a peripheral flange forming a cup-shaped recess, a thrust bearing portion in said recess adjacent the other end of said body member adapted to receive a pivot stud of a door, a roller carried by said bracket adjacent said bearing portion and a cover for said bracket engaging the upper edge of said flange and enclosing said pivot stud and roller, said flange having an opening in the lateral surface thereof adapted to receive a rack engageable with a gear on said stud and held in position by said roller.

5. A door operating mechanism comprising a door, a door operating shaft, a pair of levers mounted on the shaft for supporting said door, one of said levers forming a housing, and means for causing the door to swing and pivot as it opens and closes, a substantial portion of said means being mounted within the housing formed by one of said levers.

6. In a door operating mechanism the combination comprising a rotatably supported door shaft, a pair of levers secured to said shaft, a door pivotally mounted on said levers, and means pivotally interconnecting the door with a point fixed withrespect to the door to cause it to rotate on the levers as it swings with them, said means including a pair of relatively movable members and a spring for resisting their relative movement.

7. In a door operating mechanism the combination comprising a rotatably supported door shaft, a. motive device for rotating said shaft, a pair of levers secured to said shaft for rotation therewith, a door, means for pivotally mounting the door between said levers including a pivot pin connected to the door, means interconnecting the pivot pin with a point fixed with respect to the door to cause it to rotate as it swings, said means including a pair of relatively movable members and a spring for resisting relative movement thereof.

8. A door operating mechanism as described comprising a door shaft, a door rotatably supported on a pair of arms secured to said shaft, one of said arms being in the form of a casing, means for rotating said shaft, and means including a gear train interconnecting the door with the shaft to cause it to rotate on its axis of support on the levers as it swings with the door shaft, said gear train being within said casing.

9. A door operating mechanism comprising a power operated rotatable shaft, a pair of spaced levers connected to the shaft, a door pivotally mounted between the levers, and mechanism connected to the door for effecting combined swinging and rotative movement as the door opens including a resilient connection whereby the door may be manually opened while said mechanism is in door closed position.

ALFRED O. WILLIAMS. 

